Fatty acids and atherosclerotic risk

Impact of dietary n-6/n-3 fatty acid ratio of atherosclerosis risk: A review

Atherosclerosis is a causative factor associated with cardiovascular disease (CVD). Over the past few decades, extensive research has been carried out on the relationship between the n-6/n-3 fatty acid ratio of ingested lipids and the progression of atherosclerosis. However, there are still many uncertainties regarding the precise nature of this relationship, which has led to challenges in providing sound dietary advice to the general public. There is therefore a pressing need to review our current understanding of the relationship between the dietary n-6/n-3 fatty acid ratio and atherosclerosis, and to summarize the underlying factors contributing to the current uncertainties. Initially, this article reviews the association between the n-6/n-3 fatty acid ratio and CVDs in different countries. A summary of the current understanding of the molecular mechanisms of n-6/n-3 fatty acid ratio on atherosclerosis is then given, including inflammatory responses, lipid metabolism, low-density lipoprotein cholesterol oxidation, and vascular function. Possible reasons behind the current controversies on the relationship between the n-6/n-3 fatty acid ratio and atherosclerosis are then provided, including the precise molecular structures of the fatty acids, diet-gene interactions, the role of fat-soluble phytochemicals, and the impact of other nutritional factors. An important objective of this article is to highlight areas where further research is needed to clarify the role of n-6/n-3 fatty acid ratio on atherosclerosis.

Ruminal microbiota and muscle metabolome characteristics of Tibetan plateau yaks fed different dietary protein levels

Introduction

The dietary protein level plays a crucial role in maintaining the equilibrium of rumen microbiota in yaks. To explore the association between dietary protein levels, rumen microbiota, and muscle metabolites, we examined the rumen microbiome and muscle metabolome characteristics in yaks subjected to varying dietary protein levels.

Methods

In this study, 36 yaks were randomly assigned to three groups (n = 12 per group): low dietary protein group (LP, 12% protein concentration), medium dietary protein group (MP, 14% protein concentration), and high dietary protein group (HP, 16% protein concentration).

Results

16S rDNA sequencing revealed that the HP group exhibited the highest Chao1 and Observed_species indices, while the LP group demonstrated the lowest. Shannon and Simpson indices were significantly elevated in the MP group relative to the LP group (P < 0.05). At the genus level, the relative abundance of Christensenellaceae_R-7_group in the HP group was notably greater than that in the LP and MP groups (P < 0.05). Conversely, the relative abundance of Rikenellaceae_RC9_gut_group displayed an increasing tendency with escalating feed protein levels. Muscle metabolism analysis revealed that the content of the metabolite Uric acid was significantly higher in the LP group compared to the MP group (P < 0.05). The content of the metabolite L-(+)-Arabinose was significantly increased in the MP group compared to the HP group (P < 0.05), while the content of D-(-)-Glutamine and L-arginine was significantly reduced in the LP group (P < 0.05). The levels of metabolites 13-HPODE, Decanoylcarnitine, Lauric acid, L-(+)-Arabinose, and Uric acid were significantly elevated in the LP group relative to the HP group (P < 0.05). Furthermore, our observations disclosed correlations between rumen microbes and muscle metabolites. The relative abundance of NK4A214_group was negatively correlated with Orlistat concentration; the relative abundance of Christensenellaceae_R-7_group was positively correlated with D-(-)-Glutamine and L-arginine concentrations.

Discussion

Our findings offer a foundation for comprehending the rumen microbiome of yaks subjected to different dietary protein levels and the intimately associated metabolic pathways of the yak muscle metabolome. Elucidating the rumen microbiome and muscle metabolome of yaks may facilitate the determination of dietary protein levels.

Changes of trans and saturated fatty acid content in savory baked goods from 2015 to 2021 and their effect on consumers' intake using substitution models: A study conducted in Greece

BACKGROUND

In Greece, nearly a third of savory baked goods (SBGs) exceeded the limit of 2 g of nonruminant or industrial trans fatty acids (i-TFA) per 100 g fat in 2015. The impact of the Commission Regulation (European Union) 2019/649 on exposure to trans fatty acids (TFA), i-TFA, and saturated fatty acid (SFA) from SBGs has not been previously evaluated.

OBJECTIVES

The study aimed to explore fatty acid reformulation of SBG products and assess differences in TFA, i-TFA, and SFA intakes using a sample of Greek SBG consumers from a nationally representative survey.

METHODS

In 2021, 140 samples of SBGs were collected in the greater metropolitan area of Athens, and their fat profile and content were compared to those from 2015. Based on these measurements, food consumption substitution models were employed to examine TFA and SFA intake differences, and the percent contribution from SBG among consumers was calculated (N = 1008). Nutrient densities were calculated by adjusting all fat intakes by individual mean energy intake (percentage of daily total energy intake).

RESULTS

The 2% i-TFA legislative limit/100 g of fat in measured SBGs was exceeded by 11.4% in 2021 compared to 31.1% in 2015 (19.7% increase in compliance). Median i-TFA and TFA intakes from SBGs were reduced from 0.05 (0.01, 0.12)% and 0.13 (0.03, 0.27)% in 2015 to 0.03 (0.01, 0.09) and 0.06 (0.03, 0.13)% in 2021, respectively. In terms of SFA, a mean increase/100 g was calculated, resulting in an increased intake in 2021 compared to 2015 [5.18% (2.78, 8.37) and 3.55 (1.99, 5.73), respectively].

CONCLUSIONS

Despite the reductions seen in i-TFA content of SBGs, food product reformulation efforts in Greece should focus not only on TFA content but also on SFA reduction to improve public health.

A novel type of Brassica napus with higher stearic acid in seeds developed through genome editing of BnaSAD2 family

KEY MESSAGE

Modifications of multiple copies of the BnaSAD2 gene family with genomic editing technology result in higher stearic acid content in the seed of polyploidy rapeseed. Solid fats from vegetable oils are widely used in food processing industry. Accumulating data showed that stearic acid is more favorite as the major composite among the saturate fatty acids in solid fats in considerations of its effects on human health. Rapeseed is the third largest oil crop worldwide, and has potential to be manipulated to produce higher saturated fatty acids as raw materials of solid fats. Toward that end, we identified four SAD2 gene family members in B. napus genome and established spatiotemporal expression pattern of the BnaSAD2 members. Genomic editing technology was applied to mutate all the copies of BnaSAD2 in this allopolyploid species and mutants at multiple alleles were generated and characterized to understand the effect of each BnaSAD2 member on blocking desaturation of stearic acid. Mutations occurred at BnaSAD2.A3 resulted in more dramatic changes of fatty acid profile than ones on BnaSAD2.C3, BnaSAD2.A5 and BnaSAD2.C4. The content of stearic acid in mutant seeds with single locus increased dramatically with a range of 3.1-8.2%. Furthermore, combination of different mutated alleles of BnaSAD2 resulted in more dramatic changes in fatty acid profiles and the double mutant at BnaSAD2.A3 and BnaSAD2.C3 showed the most dramatic phenotypic changes compared with its single mutants and other double mutants, leading to 11.1% of stearic acid in the seeds. Our results demonstrated that the members of BnaSAD2 have differentiated in their efficacy as a Δ9-Stearoyl-ACP-Desaturase and provided valuable rapeseed germplasm for breeding high stearic rapeseed oil.

Protective Effect of Triclosan in Monocrotaline-Induced Pulmonary Arterial Hypertension: FASN Inhibition a Novel Approach

Background

Novel pharmacological approaches are needed to improve the outcomes of patients with idiopathic pulmonary hypertension. Fatty acid synthase (FASN) inhibitors have shown beneficial effects in preclinical models of pulmonary arterial hypertension (PAH), because of their role in the regulation of pulmonary artery vasoconstrictor tone and remodeling.

Objective

We compared a Triclosan (FASN inhibitor), for the first time with the dual endothelin receptor antagonist, macitentan, in a monocrotaline-induced rat pulmonary hypertension model.

Methods

Different methods (hemodynamics, histology of right ventricle and pulmonary vessels, and circulating biomarkers) showed consistently that 30 mg/kg daily of Triclosan (FASN inhibitor) and 10 mg/kg daily of macitentan slowed the progression of PAH both at the functional and structural levels.

Results

Treatments started on day 14 after monocrotaline injection and lasted 14 days. The findings of all experimental methods show that the FASN inhibitor has more similar effects as compared to macitentan.

Conclusion

Our study reveals that inhibition of FAS decreases RV hypertrophy and improves cardiac function associated with PAH with the regulation of metabolic functions and governs further studies to establish "FASN inhibitor as a potential therapeutic approach" for the management of PAH.

Aortic dysfunction by chronic cadmium exposure is linked to multiple metabolic risk factors that converge in anion superoxide production

CONTEXT

The chronic exposure to Cadmium (Cd) constitute an risk to develop hypertension and cardiovascular diseases associated with the increase of oxidative stress.

OBJECTIVE

In this study, we investigate the role of metabolic changes produced by exposure to Cd on the endothelial dysfunction via oxidative stress.

METHODS

Male Wistar rats were exposed to Cd (32.5-ppm) for 2-months. The zoometry and blood pressure were evaluated, also glucose and lipids profiles in serum and vascular reactivity evaluated in isolated aorta rings.

RESULTS

Rats exposed to Cd showed an increase of blood pressure and biochemical parameters similar to metabolic syndrome. Additionally, rats exposed to Cd showed a reduced relaxation in aortic rings, which was reversed after the addition of SOD and apocynin an inhibitor of NADPH.

CONCLUSION

The Cd-exposition induced hypertension and endothelial injury by that modifying the vascular relaxation and develop oxidative stress via NADPH oxidase, superoxide and loss nitric oxide bioavailability.

Factors associated to serum paraoxonase 1 activity in patients with cardiovascular disease

OBJECTIVE

Paraoxonase 1 (PON1) is an enzyme that has antioxidant potential, which confers a protective effect against the atherosclerotic process. However, studies associating genetics, dietary patterns and PON1 activity in individuals with cardiovascular disease (CVD) are scarce. Thus, the aim of the current study was to evaluate the influence of dietary factors on serum PON1 in CVD patients.

METHODS

Cross-sectional, sub-study of the BALANCE Program Trial. All patients aged 45 years or older and had evidence of established atherosclerotic disease in the preceding 10 years. Body weight, height, waist circumference, blood pressure, lipid profile and fasting glucose were collected. Food intake was assessed with 24-h dietary recall. Data was analyzed using SAS University Edition and a P value ≤ 0.05 was considered statistically significant. Sample was divided into three groups, according to the PON1 T(-107)C genotype (CC, CT and TT) and serum PON1 activity (Low, Medium, High).

RESULTS

There were no genotype differences for major factors. However, the systolic blood pressure was lower for CT individuals (p<0.05). Intake of cholesterol, saturated fatty acids (SFA) and monounsaturated fatty acids (MUFAS) was higher in patients with lower PON1 activity. Lipid ingestion tended to be higher in patients with lower PON1 activity (p=0.08). In the multivariate logistic regression model, SFA intake (P=0.03), genotype (P=0.09), gender (P=0.04), age (P=0.07) and carbohydrate intake (P=0.16) contributed the most to the serum PON1 activity.

CONCLUSION

Based on these findings, nutritional guidance for these patients becomes essential, since dietary components interact with serum PON1 activity more than genotype.

A Validated Method for Quantification of Fatty Acids Incorporated in Human Plasma Phospholipids by Gas Chromatography-Triple Quadrupole Mass Spectrometry

Fatty acids (FA) are important mediators of health maintenance and disease risk. Optimal quantification assays of FA in high and low abundance as well the identification of 13C-labeled tracers to monitor FA metabolism are of major interest. The article on hand reports about the development and validation of a gas chromatography (GC)-triple quadrupole mass selective detection (GC-TQMS) method for absolute quantification of FA in human plasma phospholipids (hpPL). The quantification of the calibration solution by GC-flame ionization detection (GC-FID), with the introduction of a correction factor, allows the direct comparison of individual FA concentrations in hpPL by GC-TQMS. Specificity, sensitivity, and reproducibility are achieved by optimized chromatographic separation and employment of GC-TQMS. The inter-method comparison between GC-FID and GC-TQMS concentrations revealed good comparability for 27 FA. A full validation has been performed with linearity over 4 magnitudes, a limit of detection of 0.18-38.3 fmol on column, a recovery of 83.6-109.6%, and intraday and interday precision data meeting the criteria of EMA and FDA guidelines. The method includes the absolute quantification of 58 positional and geometrical (cis/trans) isomeric FA in hpPL in the concentration range of 1-3000 nmol/mL, covering also low abundant positional cis/trans isomers. Results obtained from both methods are highly comparable, and selectivity and sensitivity are improved by using GC-TQMS. Additionally, we show here that calculation of 13C-labeled C16:0 tracer/tracee ratios in hpPL in human isotope enrichment studies is possible.

Comparative Analysis of Milk Triglycerides Profile between Jaffarabadi Buffalo and Holstein Friesian Cow

Milk lipids are known for a variety of biological functions, however; little is known about compositional variation across breeds, especially for Jaffarabadi buffalo, an indigenous Indian breed. Systematic profiling of extracted milk lipids was performed by mass spectrometry across summer and winter in Holstein Friesian cow and Jaffarabadi buffalo. Extensive MS/MS spectral analysis for the identification (ID) of probable lipid species using software followed by manual verification and grading of each assigned lipid species enabled ID based on (a) parent ion, (b) head group, and (c) partial/full acyl characteristic ions for comparative profiling of triacylglycerols between the breeds. Additionally, new triacylglycerol species with short-chain fatty acids were reported by manual interpretation of MS/MS spectra and comparison with curated repositories. Collectively, 1093 triacylglycerol species belonging to 141 unique sum compositions between the replicates of both the animal groups were identified. Relative quantitation at sum composition level followed by statistical analyses revealed changes in relative abundances of triacylglycerol species due to breed, season, and interaction effect of the two. Significant changes in triacylglycerols were observed between breeds (81%) and seasons (59%). When the interaction effect is statistically significant, a higher number of triacylglycerols species in Jaffarabadi has lesser seasonal variation than Holstein Friesian.

Role of free fatty acids in endothelial dysfunction

Plasma free fatty acids levels are increased in subjects with obesity and type 2 diabetes, playing detrimental roles in the pathogenesis of atherosclerosis and cardiovascular diseases. Increasing evidence showing that dysfunction of the vascular endothelium, the inner lining of the blood vessels, is the key player in the pathogenesis of atherosclerosis. In this review, we aimed to summarize the roles and the underlying mechanisms using the evidence collected from clinical and experimental studies about free fatty acid-mediated endothelial dysfunction. Because of the multifaceted roles of plasma free fatty acids in mediating endothelial dysfunction, elevated free fatty acid level is now considered as an important link in the onset of endothelial dysfunction due to metabolic syndromes such as diabetes and obesity. Free fatty acid-mediated endothelial dysfunction involves several mechanisms including impaired insulin signaling and nitric oxide production, oxidative stress, inflammation and the activation of the renin-angiotensin system and apoptosis in the endothelial cells. Therefore, targeting the signaling pathways involved in free fatty acid-induced endothelial dysfunction could serve as a preventive approach to protect against the occurrence of endothelial dysfunction and the subsequent complications such as atherosclerosis.

A combined microwave pretreatment/solvent extraction process for the production of oil from palm fruit: optimisation, oil quality and effect of prolonged exposure

BACKGROUND

Conventional palm oil milling involves multiple stages after fruit collection; in particular, oil clarification introduces water into the pressed oil, which results in a large quantity of wastewater.

RESULTS

A combined process of microwave pretreatment and solvent extraction to mill crude palm oil, without introducing water or steam, is described. An excellent yield (up to 30%) of oil was obtained with pretreatment in a 42 L, 1000 W and 2450 MHz microwave oven followed by hexane extraction. The optimum conditions (10 min microwave pretreatment and 12 h solvent extraction) yielded an oil with a low free fatty acid content (<1.0%) and an acceptable anisidine value (<3.0 meq kg^-1 ). The oil had a fatty acid composition not resembling those of conventional crude palm oil and crude palm kernel oil. In the pretreatment, the leached oil had 6.3% lauric acid whereas the solvent extracted oil had only 1.5% lauric acid. Among the factors affecting the oil quality, microwave pretreatment affected the oil quality significantly; however, an optimised duration that would ensure high efficiency in solvent extraction also resulted in ruptured fruitlets, although not to the extent of causing excessive oxidation. In fact, microwave pretreatment should exceed 12 min; after only 15 min, the oil had 1-methylcyclopentanol (12.96%), 1-tetradecanol (9.44%), 1-nonadecene (7.22%), nonanal (7.13%) and 1-tridecene (5.09%), which probably arose from the degradation of fibres.

CONCLUSION

Microwave pretreatment represents an alternative milling process for crude palm oil compared with conventional processes in the omission of wet treatment with steam. © 2016 Society of Chemical Industry.

The Korean herbal medicine, Do In Seung Gi-Tang, attenuates atherosclerosis via AMPK in high-fat diet-induced ApoE(-/-) mice

Background

Do In Seung Gi-Tang (DISGT) is an herbal mixture of traditional Korean medicine that is composed of Rheum undulatum Linne, Prunus Persica (L.) Batsch, Conyza canadensis L., Cinnamomum Cassia Presl, and Glycytthiza uralensis Fischer (8: 6: 4: 4: 4 ratio). We investigated the effect of DISGT on vascular inflammation and lipid accumulation in apolipoprotein E-deficient (ApoE^−/−) mice.

Methods

ApoE^−/− mice that were fed a high-fat diet (HFD) were treated with DISGT (300 mg/kg/day) or statin (10 mg/kg/day) for 16 weeks. Serum lipid levels were analyzed. Oil Red O staining was used to evaluate atherosclerotic lesions and lipid accumulation in the aorta and liver, respectively. The expression of adhesion molecules (intercellular adhesion molecule-1 [ICAM-1], vascular cell adhesion molecule-1 [VCAM-1], and E-selectin), fatty acid synthase (FAS), adenosine monophosphate-activated protein kinase (AMPK), and acetyl-coA carboxylase (ACC) in the aorta or liver tissues was measured by western blot analysis. Lipid synthesis and inflammatory responses were assessed by immunohistochemistry and hematoxylin & eosin staining, respectively.

Results

Treatment of HFD-fed mice with DISGT significantly lowered body weight, liver weight, and the levels of lipids, including total cholesterol, low-density lipoprotein-cholesterol, and triglycerides. Glucose levels were also lowered. In the aorta, DISGT attenuated atherosclerotic lesions and reduced the expression of ICAM-1, VCAM-1, and E-selectin. Moreover, DISGT decreased lipid accumulation, inflammatory responses, and FAS levels, and it activated AMPK and reduced ACC expression in liver tissues.

Conclusions

The beneficial, anti-lipolytic, and anti-inflammatory effects of DISGT were mediated by the AMPK pathway. As a result, the expression of inflammatory factors was reduced. Our data provide evidence that DISGT may have strong therapeutic potential in treating vascular diseases, such as atherosclerosis.

Dietary fats and health: dietary recommendations in the context of scientific evidence

Although early studies showed that saturated fat diets with very low levels of PUFAs increase serum cholesterol, whereas other studies showed high serum cholesterol increased the risk of coronary artery disease (CAD), the evidence of dietary saturated fats increasing CAD or causing premature death was weak. Over the years, data revealed that dietary saturated fatty acids (SFAs) are not associated with CAD and other adverse health effects or at worst are weakly associated in some analyses when other contributing factors may be overlooked. Several recent analyses indicate that SFAs, particularly in dairy products and coconut oil, can improve health. The evidence of ω6 polyunsaturated fatty acids (PUFAs) promoting inflammation and augmenting many diseases continues to grow, whereas ω3 PUFAs seem to counter these adverse effects. The replacement of saturated fats in the diet with carbohydrates, especially sugars, has resulted in increased obesity and its associated health complications. Well-established mechanisms have been proposed for the adverse health effects of some alternative or replacement nutrients, such as simple carbohydrates and PUFAs. The focus on dietary manipulation of serum cholesterol may be moot in view of numerous other factors that increase the risk of heart disease. The adverse health effects that have been associated with saturated fats in the past are most likely due to factors other than SFAs, which are discussed here. This review calls for a rational reevaluation of existing dietary recommendations that focus on minimizing dietary SFAs, for which mechanisms for adverse health effects are lacking.

Super, red palm and palm oleins improve the blood pressure, heart size, aortic media thickness and lipid profile in spontaneously hypertensive rats

BACKGROUND

Oleic acid has been shown to lower high blood pressure and provide cardiovascular protection. Curiosity arises as to whether super olein (SO), red palm olein (RPO) and palm olein (PO), which have high oleic acid content, are able to prevent the development of hypertension.

METHODOLOGY/PRINCIPAL FINDINGS

Four-week-old male spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats were fed 15% SO, RPO or PO supplemented diet for 15 weeks. After 15 weeks of treatment, the systolic blood pressure (SBP) of SHR treated with SO, RPO and PO were 158.4±5.0 mmHg (p<0.001), 178.9±2.7 mmHg (p<0.001) and 167.7±2.1 mmHg (p<0.001), respectively, compared with SHR controls (220.9±1.5 mmHg). Bradycardia was observed with SO and PO. In contrast, the SBP and heart rate of treated WKY rats were not different from those of WKY controls. The SO and PO significantly reduced the increased heart size and thoracic aortic media thickness observed in untreated SHR but RPO reduced only the latter. No such differences, however, were observed between the treated and untreated WKY rats. Oil Red O enface staining of thoracic-abdominal aorta did not show any lipid deposition in all treated rats. The SO and RPO significantly raised serum alkaline phosphatase levels in the SHR while body weight and renal biochemical indices were unaltered in both strains. Serum lipid profiles of treated SHR and WKY rats were unchanged, with the exception of a significant reduction in LDL-C level and total cholesterol/HDL ratio (atherogenic index) in SO and RPO treated SHR compared with untreated SHR.

CONCLUSION

The SO, RPO and PO attenuate the rise in blood pressure in SHR, accompanied by bradycardia and heart size reduction with SO and PO, and aortic media thickness reduction with SO, RPO and PO. The SO and RPO are antiatherogenic in nature by improving blood lipid profiles in SHR.

Multiple aberrations in shared inflammatory and oxidative & nitrosative stress (IO&NS) pathways explain the co-association of depression and cardiovascular disorder (CVD), and the increased risk for CVD and due mortality in depressed patients

There is evidence that there is a bidirectional relationship between major depression and cardiovascular disorder (CVD): depressed patients are a population at risk for increased cardiac morbidity and mortality, and depression is more frequent in patients who suffer from CVD. There is also evidence that inflammatory and oxidative and nitrosative stress (IO&NS) pathways underpin the common pathophysiology of both CVD and major depression. Activation of these pathways may increase risk for both disorders and contribute to shared risk. The shared IO&NS pathways that may contribute to CVD and depression comprise the following: increased levels of pro-inflammatory cytokines, like interleukin-1β (IL-1β), IL-2, IL-6, IL-8, IL-12, tumor necrosis factor-α, and interferon-γ; T cell activation; increased acute phase proteins, like C-reactive protein, haptoglobin, fibrinogen and α1-antitrypsin; complement factors; increased LPS load through bacterial translocation and subsequent gut-derived inflammation; induction of indoleamine 2,3-dioxygenase with increased levels of tryptophan catabolites; decreased levels of antioxidants, like coenzyme Q10, zinc, vitamin E, glutathione and glutathione peroxidase; increased O&NS characterized by oxidative damage to low density lipoprotein (LDL) and phospholipid inositol, increased malondialdehyde, and damage to DNA and mitochondria; increased nitrosative stress; and decreased ω3 polyunsaturated fatty acids (PUFAs). The complex interplay between the abovementioned IO&NS pathways in depression results in pro-atherogenic effects and should be regarded as a risk factor to future clinical CVD and due mortality. We suggest that major depression should be added as a risk factor to the Charlson "comorbidity" index. It is advised that patients with (sub)chronic or recurrent major depression should routinely be assessed by serology tests to predict if they have an increased risk to cardiovascular disorders.

Effects of oxidized cooking oil and α-lipoic acid on liver antioxidants: enzyme activities and lipid peroxidation in rats fed a high fat diet

The effects of administration of oxidized rapeseed oil and α-lipoic acid on activities of hepatic antioxidant enzymes and lipid peroxidation were studied in laboratory rats. There was an increase of the activities of superoxide dismutase, glutathione peroxidase, glutathione reductase, and glucose-6-phosphate dehydrogenase in rats fed a high fat diet to which 10% oxidized oil was added. Administration of α-lipoic acid resulted in a decrease of the activities of these enzymes. Addition of oxidized oil also resulted in increased production of oxygen radicals, evidenced by elevated malondialdehyde production. Such effect was counteracted by administration of α-lipoic acid.

Lipidomics analysis of essential fatty acids in macrophages

The Lipid Metabolites and Pathway Strategy (LIPID MAPS) Consortium is a nationwide initiative that has taken on the task of employing lipidomics to advance our understanding of lipid metabolism at the molecular and mechanistic level in living organisms. An important step toward this goal is to craft enabling analytical procedures to comprehensively measure all lipid species, to establish the precise structural identity of the lipid molecules analyzed, and to generate accurate quantitative information. The LIPID MAPS Consortium has succeeded in the implementation of a complete infrastructure that now provides tools for analysis of the global lipidome in cultured and primary cells. Here we illustrate the advancement of a gas chromatography mass spectrometry (GC/MS) procedure for the analysis of essential fatty acids in RAW 264.7 cells. Our method allows for the specific identification and quantification of over 30 fatty acids present in cells in their free form in a single analytical GC/MS run. Free fatty acids are selectively extracted in the presence of deuterated internal standards, which permit subsequent estimation of extraction efficiencies and quantification with high accuracy. Mass spectrometer conditions were optimized for single-ion monitoring, which provides an extremely sensitive technology to measure fatty acids from biological samples in trace amounts. These methods will be presented in the context of our broader effort to analyze all fatty acids as well as their metabolites in inflammatory cells.

Signalling pathways controlling fatty acid desaturation

Microorganisms, plants and animals regulate the synthesis of unsaturated fatty acids (UFAs) during changing environmental conditions as well as in response to nutrients. Unsaturation of fatty acid chains has important structural roles in cell membranes: a proper ratio of saturated to UFAs contributes to membrane fluidity. Alterations in this ratio have been implicated in various disease states including cardiovascular diseases, immune disorders, cancer and obesity. They are also the major components of triglycerides and intermediates in the synthesis of biologically active molecules such as eicosanoids, which mediates fever, inflammation and neurotransmission. UFAs homeostasis in many organisms is achieved by feedback regulation of fatty acid desaturases gene transcription. Here, we review recently discovered components and mechanisms of the regulatory machinery governing the transcription of fatty acid desaturases in bacteria, yeast and animals.

Paraoxonase 1 response to a high-fat diet: gender differences in the factors involved

Diets consumed in industrialized countries are rich in fat and increase the incidence of atherosclerosis, a process reported to be influenced by gender. Considering the anti-atherogenic role attributed to serum Paraoxonase 1 (PON1) activity, and given the pro-atherogenic effects described for saturated fatty acids (SFA), as opposed to the beneficial ones conferred to monounsaturated fatty acids (MUFA), the aim of this study was to investigate the response of male and female rat serum PON1 activity and its related factors to a high-fat (HF), hypercaloric diet (fat representing 55.2% of the energy) containing similar amounts of SFA and MUFA. The HF diet feeding did not alter total body weight, but increased adiposity. Nevertheless, and in spite of the increased adiposity, the HF diet did not entail a more pro-inflammatory serum adipokine or lipid profile or increased lipid peroxidation. Paraoxonase activity was reduced in both male and female HF fed rats, due to a reduction of PON1 mRNA levels in males and to a reduced stability and/or number of HDL particles responsible for PON1 transport in females. Both the maintenance of body weight and the MUFA content in the diet would be among the factors responsible for the attenuation of the negative effects usually related to excessive fat intake and for the reduction in PON activity, whose antioxidant activity would be less necessary in this situation.

Control of fatty acid desaturation: a mechanism conserved from bacteria to humans

Unsaturated fatty acids (UFAs) have profound effects on the fluidity and function of biological membranes. Microorganisms, plants and animals regulate the synthesis of UFAs during changing environmental conditions as well as in response to nutrients. UFAs homeostasis in many organisms is achieved by feedback regulation of fatty acid desaturase gene transcription through signalling pathways that are governed by sensors embedded in cellular membranes. Here, we review recently discovered components of the regulatory machinery governing the transcription of fatty acid desaturases in bacteria, yeasts and animals that indicate an ancient role of transmembrane signalling mechanisms and integrate membrane composition with lipid biosynthesis.